June 25, 2009
The "Olla" Technique for Deep Watering
It is raining right now, hurray, but rain cannot be counted on here in the Southwest. For certain flower and vegetable beds, soaker hoses or permanent drip-irrigation systems are not an option and my house, but "ollas" (Spanish for jug) work, even in our heavy clay foothills soil.
Supposedly this is an old Pueblo Indian technique—bury an unglazed clay pot with just the neck showing and then fill it as needed.
The top photo shows two models. The vinegar jug at left (heavier than a milk jug) is pierced with multiple holes (that do not show up well), made with a hot awl. The other olla consists of two flower pots joined by Blue RTV Silicone and with a stopper in the lower pot's drain hole.
Each has its pros and cons:
1. Plastic jug: Quick, easy, cheap, but will disintegrate from ultraviolet light in two years.
2. Clay pots: Breakable, must be purchased, last longer, diffuse water more gradually.
Here are two jugs with potatoes planted around them, the photo having been taken in early June. The funnel is for filling. In clay soils, the water will not seep out very far from the jug, so plants must go right next to it. The pine needles are mulch—a little difficult to arrange, but free for the gathering nearby.
Surface watering on clay soil often pools and runs off, but the jugs can release water deeper down, within a small radius.